ORNL-1771 - Oak Ridge National Laboratory

ANP QUARTERLY PROGRESS REPORT
TABLE 8.1. VAPOR PRESSURE IN NaF-ZrF4
(25-75 mole W) SYSTEM
_ _ ~ ~
T e t il pe ra tu re
("C)
754
769
7 76
786
796
805
81 1
82 8
844
Ob served Calculated
Pressure Pressure
(mnl ng) (mm i-lg) FILM, 04 mil
29
37
44
54
66
74
83
115
152
28
38
44
54
65
76
83
115
155
the intersection of the vapor pressure curve with
that of pure ZrF,, is about 760°C.
FUSED-SALT HEAT TRANSFER
ti. W. Hoffman
Reactor Experimental Engineering Divi sion
Additional data for NaF-KF-LiF (1 1.5-42.0-46.5
mole 75) flawing for short-time periods in an electrically
heated type 316 stainless steel tube have
been analyzed. The results are in agreement with
the general turbulent flow correlations for ordinary
fluids.
The thermal conductivity of K,CrF, was found
to be 0.13 Btu/hr.ft2 ("F/ft)9 in the temperature
range 100 to 2000F. Measurements from a photo-
micrograph, Fig. 8.2, of a section of the tube used
in the lnconel experiment show a film thickness
of about 0.4 mil. The thermal resistance calcu-
lated from these results, 0.00025 hr-ft'." F/Btu, is
in agreement with the measured thermal resistance
obtained from the heat transfer experiments in the
lnconel system.
The forced-convection apparatus," which is to
be used for studying the rate of growth of wall
deposits, as well as for heat transfer meaiuremerits
of fused fluoride mixtures, has been operated
successfully for more than 100 hr with the heat
'H. W. Hoffman and J. Lones, ANP Qunr. frog. Rep.
June 10, 1954, ORNL-1729, p 101.
"1-1. W. Hoffman and J. Lones, ANP Quar. frog. Rep.
Mai-. 10, 1954, ORNL-1692, p 98.
130
Fig. 8.2. incone! Tube with Film Deposit of
K,CKF,.
transfer salt NaN0,-NaN0,-KNQ, (40-7-53 wt %)
as the circulated fluid. The system is now being
modified so that resistance-heated, as well as
externally heated, test sections can be inserted
in the system. With resistance-heated sections,
larger axial fluid temperature rises can be attained.
It is planned to study next a zirconiumuranium
fluoride salt mixture in Inconel.
TRANSIENT BOlLlNG RESEARCH
M. W. Rosenthal
Reactor Exper irnenta I Eng i neer i ng Bi v i si on
A study of the heat transfer phenomena which
occur when a water-cooled and -moderated solidf
ue I -element reactor sudden ly becomes super -
critical has been undertaken. The time required
for generotion of steam in water which is initially
below the boiling point will be determined. The
effects of water temperature, rate of power increase,
air concentration, and surface condition
will be investigated.
Construction of the equipment for generation of
power surges by electrical means in aluminum filaments
has been completed, and the entire experimental
apparatus has been assembled and tested.
Satisdactory operation has been achieved. The
transient-power generator consists of 100 thyratrons
connected in parallel. A different bias
can be put on the grid of each thyratron, and the
system can he set so that a signal of increasing
voltage applied simultaneously to all tubes fires
them in a sequence that approximates the desired
function. A peak current of about 500 amp can be
produced, with the duration of the power surge
ranging from 30 to 500 msec.
The instantaneous values of voltage drop across
the test filament and current through it are recorded
by n fast-response Hathaway oscillograph.
A Fastax high-speed motion picture camera is